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path: root/drivers/char/ramoops.c
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2011-01-13ramoops: fix types, remove typecastsAndrew Morton
Cc: Ahmed S. Darwish <darwish.07@gmail.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marco Stornelli <marco.stornelli@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13kmsg_dump: constrain mtdoops and ramoops to perform their actions only for ↵Seiji Aguchi
KMSG_DUMP_PANIC This series aims to develop logging facility for enterprise use. It is important to save kernel messages reliably on enterprise system because they are helpful for diagnosing system. This series add kmsg_dump() to the paths loosing kernel messages. The use case is the following. [Use case of reboot/poweroff/halt/emergency_restart] My company has often experienced the followings in our support service. - Customer's system suddenly reboots. - Customers ask us to investigate the reason of the reboot. We recognize the fact itself because boot messages remain in /var/log/messages. However, we can't investigate the reason why the system rebooted, because the last messages don't remain. And off course we can't explain the reason. We can solve above problem with this patch as follows. Case1: reboot with command - We can see "Restarting system with command:" or ""Restarting system.". Case2: halt with command - We can see "System halted.". Case3: poweroff with command - We can see " Power down.". Case4: emergency_restart with sysrq. - We can see "Sysrq:" outputted in __handle_sysrq(). Case5: emergency_restart with softdog. - We can see "Initiating system reboot" in watchdog_fire(). So, we can distinguish the reason of reboot, poweroff, halt and emergency_restart. If customer executed reboot command, you may think the customer should know the fact. However, they often claim they don't execute the command when they rebooted system by mistake. No message remains on the current Linux kernel, so we can't show the proof to the customer. This patch improves this situation. This patch: Alters mtdoops and ramoops to perform their actions only for KMSG_DUMP_PANIC, KMSG_DUMP_OOPS and KMSG_DUMP_KEXEC because they would like to log crashes only. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marco Stornelli <marco.stornelli@gmail.com> Reviewed-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-28RAMOOPS: Don't overflow over non-allocated regionsAhmed S. Darwish
The current code mis-calculates the ramoops header size, leading to an overflow over the next record at best, or over a non-allocated region at worst. Fix that calculation. Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: Marco Stornelli <marco.stornelli@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27ramoops: use the platform data structure instead of module paramsKyungmin Park
As each board and system has different memory for ramoops. It's better to define the platform data instead of module params. [akpm@linux-foundation.org: fix ramoops_remove() return type] Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marco Stornelli <marco.stornelli@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27char drivers: RAM oops/panic loggerMarco Stornelli
Ramoops, like mtdoops, can log oops/panic information but in RAM. It can be used with persistent RAM for systems without flash support. In addition, for this systems, with this driver, it's no more needed add to the kernel the mtd subsystem with advantage in footprint. It can be used in a very easy way with persistent RAM for systems without flash support. For these systems, with this driver, it is no longer required to cinlude mtd subsystem with an advantage in footprint. In addition, you can save flash space and store this information only in RAM. Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com> Cc: Simon Kagstrom <simon.kagstrom@netinsight.net> Cc: David Woodhouse <David.Woodhouse@intel.com> Cc; Anders Grafstrom <anders.grafstrom@netinsight.net> Cc: Yuasa Yoichi <yuasa@linux-mips.org> Cc: Jamie Lokier <jamie@shareable.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>